MAPbI3 single crystal derived precursor ink for stable and efficient perovskite solar cells

MAPbI3 perovskite absorber ink is obtained by vapor mediated approach from MAPbI3 single crystals by exposing it to methylamine vapor for application in perovskite solar cells (PSC). This single crystal-derived ink shows a significant blue shift in the steady state photoluminescence emission due to MAPbI3 lattice slicing. Absorber films coated by spin coating process using single crystal derived MAPbI3 ink show better charge extraction, carrier lifetime, and device performance than the conventional powder derived film. Power conversion efficiency (PCE) of 16.7% is recorded for single crystal derived PSC compared to 12% of the conventional powder derived PSC demonstrating superior film quality. Highly crystalline films with lower traps and uniform absorbance in the entire visible region resulted in enhanced JSC (23.7 mA/cm2). A high fill factor (70%) is achieved due to the dense, pinhole free films with long columnar grains resulting in low series and high shunt resistance. Single crystal derived PSCs were stable with 85% (70%) PCE retention for up to 2850 h (∼3500 h) when the devices were kept in ambient (25 ± 3 °C and 50 ± 10% RH); the highest reported so far. Tests under similar conditions using conventional powder derived devices degraded within 700 h with less than 50% PCE retention. The MAPbI3 absorber layer coated using single crystal derived ink exhibits superior photovoltaic performance and stability over the conventional MAPbI3 film derived from powder precursors.